Re: HELP: 93 Toyota Corolla vibration problem!

"Mike" <mik@[EMAIL PROTECTED]
> wrote in message 
news:ttTPj.2065$Cn4.968@[EMAIL PROTECTED]
>>>>>>>> Replace both front brake hoses, replace the brake fluid, and
bleed 
>>>>>>>> the
>>>>>>>> brakes.
>>>>>>>
>>>>>>> Ray, I had them do this.  The problem still persists.  Could it be
a
>>>>>>> brake booster problem?
>>>>>>
>>>>>> I read through most of the posts before responding.
>>>>>>
>>>>>> It is very unlikely that a master cylinder is causing the problem, 
>>>>>> and it
>>>>>> is
>>>>>> unlikely that a misadjusted push rod is causing the problem unless
>>>>>> someone
>>>>>> messed with the master cylinder or pushrod.
>>>>>>
>>>>>> It is possible, but not likely that a bad wheel bearing is causing 
>>>>>> the
>>>>>> problem.  Wheel bearings generally make a lot of noise before
getting 
>>>>>> bad
>>>>>> enough to actually cause a problem.
>>>>>>
>>>>>> A wheel or tire that is out of round either laterally or radially 
>>>>>> will
>>>>>> cause
>>>>>> a vibration, but not likely that the vibration will come and go and

>>>>>> it
>>>>>> will
>>>>>> not make the wheel hot to the touch or bind the brakes so that is
not
>>>>>> high
>>>>>> on my list.
>>>>>>
>>>>>> A bad CV joint will make noise, cause pulling, or fling grease all 
>>>>>> over
>>>>>> the
>>>>>> undercarriage before it causes an intermittent vibration and will
not
>>>>>> make
>>>>>> the wheel hot to the touch or bind the brakes.
>>>>>>
>>>>>> If replacing the calipers did not change the problem, I would have
>>>>>> guessed a
>>>>>> bad brake hose.
>>>>>>
>>>>>> I read that you are replacing the front calipers, make sure that
the
>>>>>> slides
>>>>>> are free and coated with disc brake grease or anti-seize.
>>>>>>
>>>>>> Where are you located?
>>>>>
>>>>> I will add one additional possibility that I personally experienced
on 
>>>>> an
>>>>> Acura TL.  A bad upper ball joint caused ALL the symptoms re****ted 
>>>>> here on
>>>>> that car - hot wheel, apparent warping of the rotor, chattering 
>>>>> brakes,
>>>>> all
>>>>> of it.
>>>>
>>>>
>>>> You know, IF a wheel threw a weight off it could do the same thing.
>>>>
>>>>
>>> Throwing a weight causes a constant vibration.  This was different and

>>> was
>>> confirmed to be the ball joint on the TL.
>>
>> Usually throwing a weight will cause vibration at certain speeds.
Depends 
>> on the size of the wheel weight. Big ones act more harshly when missing

>> than small ones. Remember he said the wheel DOES have a small wobble to

>> it. Maybe move a rear wheel up front. Try that for a couple days.

>  Would a missing wheel weight also cause the brakes to apply and make 
the 
> vehicle slow down ???  That's what he stated is also happening.

    Did he say the brakes APPLIED?  That isn't what I read. He said he
felt 
he had to add pressure to the gas pedal. Without being there driving the 
car, my best answer to you is YES. If a wheel is out on the side to side 
axis, it CAN appear at a specific speed that the brakes are on. That's NOT

what's really happening.
You can demonstrate this for yourself the next time you are in a car. Roll

down the window and put your hand out. Try different positions for your 
hand. Flat to the flow of air, then rotate it side to side on the
horizontal 
axis. If you can look at the instruments at the same time (assuming you
are 
NOT the driver) you'll see that it actually CAN slow the car down a
little. 
Same if the wheel isn't straight in the rolling axis as the wheel
revolves. 
Actually there are more than two. They can be affected in all of them. 
Caster, Camber and so on. Wheel balance, front end alignment. Some things 
have been rules out others NOT.

    I am one, having been a partner in a parts jobber that doesn't have 
complete confidence in replacement parts. We have a 15 year old car with 
almost 300,000 miles on it.  We also have a couple smart ass dealer
mechanic 
types here that have ALL the answers. They didn't read that he had already

tried their "SURE FIRE IT ABSOLUTELY IS" stuff and it didn't work. We all 
with have 20/20 hindsight when the problem is traced down. Right now all
we 
all can do is guess.